Audio volume silders not working with 5.1 channel audio card

### Compositor

- [x] Niri
- [ ] Hyprland
- [ ] MangoWC (dwl)
- [ ] Sway

### Distribution

- [ ] Arch Linux
- [ ] CachyOS
- [ ] Fedora
- [ ] NixOS
- [x] Debian
- [ ] Ubuntu
- [ ] Gentoo
- [ ] OpenSUSE
- [ ] Other (specify below)

### If Other, please specify

_No response_

### dms version

v1.0.0-2819

### Description

I'm having an issue where DMS doesn't like my 5.1 channel card. works fine with headphones and all that but this card nopes out and won't work with the volume sliders or any commands i send to manipulate the volume. I *think* it is because it reports the volume as a decimal rather than a percent and so the system breaks down but that's just a theory.

This sound device is this if you are curious:
ID 0d8c:0102 C-Media Electronics, Inc. CM106 Like Sound Device

### Expected Behavior

sliders work with any audio device i throw at it

### Steps to Reproduce & Installation Method

adjust sliders on a card that doesn't output current volume in percent?

### Error Messages/Logs

_No response_

### Screenshots/Recordings

_No response_

Start by reproducing the failure on Debian with the C-Media CM106 5.1 audio device, testing both the volume sliders and volume commands. Compare how this device reports its current volume with a working headphone device; done means both controls work reliably for the 5.1 card.

Written by the indexing model from the issue text.